公开(公告)号：US20240275481A1

公开(公告)日：2024-08-15

申请号：US18413745

申请日：2024-01-16

Applicant: NEC Corporation

Inventor： Keiichi MATSUMOTO

IPC: H04B10/077

CPC classification number: H04B10/0771

Abstract: A monitoring system includes a monitoring device including an optical transmitter and an optical receiver, an optical repeater, and a first MCF transmission path and a second MCF transmission path, each of the paths includes cores, and connects the monitoring device and the optical repeater with each other via the plurality of cores, the optical transmitter generates an optical pulse, and inputs the optical pulse to a first core included in the cores of the first MCF transmission path, the optical repeater loops-back the optical pulse being received from the first core to a second core included in the cores of the second MCF transmission path, and the optical receiver receives the optical pulse being looped-back, as an optical reception pulse, from the cores of the second MCF transmission path, and calculates a corrected reception level, based on the optical reception pulse.

公开(公告)号：US20220166179A1

公开(公告)日：2022-05-26

申请号：US17601152

申请日：2020-04-02

Applicant: NEC Corporation

Inventor： Hitoshi TAKESHITA ,  Keiichi MATSUMOTO ,  Shigeyuki YANAGIMACHI

IPC: H01S3/067 ,  H01S3/13 ,  G02B6/02 ,  H04B10/291

Abstract: It is difficult to construct an optical fiber transmission system enabling relay optical amplification using a coupled multi-core optical fiber as an optical transmission path; therefore, an optical amplification device includes first optical spatial layout converting means for converting a spatial layout of a plurality of optical signal beams propagating through each of a plurality of cores, from a coupled state in which optical signal beams interfere between a plurality of cores to a non-coupled state in which optical signal beam interference is reduced between a plurality of cores; optical amplifying means for amplifying, in the non-coupled state, the plurality of optical signal beams with the non-coupled state and generating a plurality of amplified optical signal beams; and second optical spatial layout converting means for converting a spatial layout of the plurality of amplified optical signal beams from the non-coupled state to the coupled state.

公开(公告)号：US20210194218A1

公开(公告)日：2021-06-24

申请号：US16606290

申请日：2017-04-20

Applicant: NEC CORPORATION

Inventor： Emmanuel LE TAILLANDIER DE GABORY ,  Shigeyuki YANAGIMACHI ,  Shigeru NAKAMURA ,  Keiichi MATSUMOTO

IPC: H01S5/50 ,  H01S5/40 ,  H01S5/04 ,  H01S5/026

Abstract: It is necessary to reduce the power consumption of a plurality of optical amplifiers when there is a difference in the required pumping power between the plurality of optical amplifiers; therefore, an optical amplifying apparatus according to an exemplary aspect of the invention includes a plurality of optical amplifying means for amplifying a plurality of optical signals, each of the plurality of optical amplifying means including a gain medium; a plurality of laser light generating means for generating a plurality of laser beams; at least one optical coupling means for coupling the plurality of laser beams variably in accordance with a coupling factor and outputting a plurality of excitation light beams, each of the plurality of excitation light beams exciting the gain medium; and controlling means for controlling the coupling factor and an output power of each of the plurality of laser light generating means.

公开(公告)号：US20210057871A1

公开(公告)日：2021-02-25

申请号：US17043488

申请日：2018-03-30

Applicant: NEC Corporation

Inventor： Keiichi MATSUMOTO ,  Emmanuel LE TAILLANDIER DE GABORY

IPC: H01S3/10 ,  H01S3/067 ,  H01S3/094 ,  H04B10/50 ,  H04B10/2581 ,  H04B10/61

Abstract: A pumping light source outputs pumping lights. A pumping light source outputs a pumping light. Optical multiplexers couple the pumping lights to a plurality of cores. The optical multiplexer couples the pumping light to the clad. A pumping light source drive unit drives a pumping light source. A pumping light source drive unit drives a pumping light source. A monitoring unit outputs a monitoring signal indicating a monitoring result of the number of wavelengths used in each of optical signals amplified by the plurality of the cores. The control unit controls the power of the pumping lights based on the monitoring signal. The control unit controls the power of each of the pumping lights in accordance with the number of wavelengths used in each of the optical signals and controls the power of the pumping light so that signal qualities of the optical signals fall within a prescribed range.